image-js/lib/image/core/kind.js

Image processing and manipulation in JavaScript

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.createPixelArray = createPixelArray;
exports.getKind = getKind;
exports.getTheoreticalPixelArraySize = getTheoreticalPixelArraySize;
exports.verifyKindDefinition = verifyKindDefinition;
var ColorModel = _interopRequireWildcard(require("../model/model"));
var Kind = _interopRequireWildcard(require("./kindNames"));
function _getRequireWildcardCache(e) { if ("function" != typeof WeakMap) return null; var r = new WeakMap(), t = new WeakMap(); return (_getRequireWildcardCache = function (e) { return e ? t : r; })(e); }
function _interopRequireWildcard(e, r) { if (!r && e && e.__esModule) return e; if (null === e || "object" != typeof e && "function" != typeof e) return { default: e }; var t = _getRequireWildcardCache(r); if (t && t.has(e)) return t.get(e); var n = { __proto__: null }, a = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var u in e) if ("default" !== u && {}.hasOwnProperty.call(e, u)) { var i = a ? Object.getOwnPropertyDescriptor(e, u) : null; i && (i.get || i.set) ? Object.defineProperty(n, u, i) : n[u] = e[u]; } return n.default = e, t && t.set(e, n), n; }
const kinds = {};
kinds[Kind.BINARY] = {
  components: 1,
  alpha: 0,
  bitDepth: 1,
  colorModel: ColorModel.GREY
};
kinds[Kind.GREYA] = {
  components: 1,
  alpha: 1,
  bitDepth: 8,
  colorModel: ColorModel.GREY
};
kinds[Kind.GREY] = {
  components: 1,
  alpha: 0,
  bitDepth: 8,
  colorModel: ColorModel.GREY
};
kinds[Kind.RGBA] = {
  components: 3,
  alpha: 1,
  bitDepth: 8,
  colorModel: ColorModel.RGB
};
kinds[Kind.RGB] = {
  components: 3,
  alpha: 0,
  bitDepth: 8,
  colorModel: ColorModel.RGB
};
kinds[Kind.CMYK] = {
  components: 4,
  alpha: 0,
  bitDepth: 8,
  colorModel: ColorModel.CMYK
};
kinds[Kind.CMYKA] = {
  components: 4,
  alpha: 1,
  bitDepth: 8,
  colorModel: ColorModel.CMYK
};
function getKind(kind) {
  const result = kinds[kind];
  if (!result) {
    throw new RangeError(`invalid image kind: ${kind}`);
  }
  return result;
}
const validBitDepth = [1, 8, 16, 32];
function verifyKindDefinition(definition) {
  const {
    components,
    alpha,
    bitDepth,
    colorModel
  } = definition;
  if (!Number.isInteger(components) || components <= 0) {
    throw new RangeError(`invalid components: ${components}. Must be a positive integer`);
  }
  if (alpha !== 0 && alpha !== 1 && typeof alpha !== 'boolean') {
    throw new TypeError(`invalid alpha: ${alpha}: must be a boolean, 0 or 1`);
  }
  if (!validBitDepth.includes(bitDepth)) {
    throw new RangeError(`invalid bitDepth: ${bitDepth}. Must be one of ${validBitDepth.join(', ')}`);
  }
  // eslint-disable-next-line import/namespace
  if (!ColorModel[colorModel]) {
    throw new RangeError(`invalid colorModel: ${colorModel}. Must be one of ${Object.keys(ColorModel).join(', ')}`);
  }
}
function getTheoreticalPixelArraySize(size, channels, bitDepth) {
  let length = channels * size;
  if (bitDepth === 1) {
    length = Math.ceil(length / 8);
  }
  return length;
}
function createPixelArray(size, components, alpha, channels, bitDepth, maxValue) {
  const length = channels * size;
  let arr;
  switch (bitDepth) {
    case 1:
      arr = new Uint8Array(Math.ceil(length / 8));
      break;
    case 8:
      arr = new Uint8Array(length);
      break;
    case 16:
      arr = new Uint16Array(length);
      break;
    case 32:
      arr = new Float32Array(length);
      break;
    default:
      throw new Error(`Cannot create pixel array for bit depth ${bitDepth}`);
  }

  // alpha channel is 100% by default
  if (alpha) {
    for (let i = components; i < arr.length; i += channels) {
      arr[i] = maxValue;
    }
  }
  return arr;
}